Valve abkawg-ement of steam-engines



UNITED sTATWEs PATENT oEEmE.

HENRY CLAYTON, OF TAMAQUA, PENNSYLVANIA.

VALVE .ARRANGEMENT OF STEAM-ENGINES.

Specification of Letters Patent No. 23,448, dated April 5, 1859.

To all whom it may concern:

Be it known that I, HENRY CLAYTON, of Tamaqua, in the county of Schuylkill and State of Pennsylvania, have invented a new and useful Improvement in 'Direct-Action Steam-Engines; and I do hereby declare thatI the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specifica-tion, in which- Figure l, is a side view of a pumping engine with my invention applied, exhibiting the steam valve and apparatus for operating the same in section. Fig. 2, is a transverse section of the same in the plane indicated by the line m, a', in Fig. l. Fig. 3, is a section of the exhaust box of the small engine which operates the main valve. Fig. 4 is a front view of one of the adjustable sliding shutters applied to the ports of fthe main valve.

Similar letters of reference indicate like parts in all the ligures.

My invention is applicable to direct-action engines for all purposes, such as pumping, or driving piston blowers, reciprocating saws, or any machinery or apparatus which requires a reciprocating rectilinear motion only.

One feature of my invention is more particularly intended for engines in which the resistance to the movement of the piston or force required to drive it is greater in one direction than in the other, as for instance the pumping engines employed in raising water from mines. This feature consists in the employment, in combination with a slide valve .which is constructed with ports to admit the steam to the cylinder ports, of one or more adjustable shutters, that is to say, one shutter for either or each port, so applied as to permit the area of opening of one or both ports to be varied or adjusted according to the amount of steam required to act upon the piston. By this means I am enabled to overcome the many difficulties which have heretofore attended the raising of water from mines of great dept-h and the use of pump rods of such enormous weight as are indispensable in such cases.

Another feature of my invention relates to the driving of slide valves applied to direct-action steam engines, by a small steam engine provided for the purpose; and this feature consists in a certain mode of applying a valve to control the exhaust of the steam from the cylinder of such smaller engine for the purpose of making it constitute a cushion within said cylinder to regulate the length of stroke of the valve-driving piston.

To enable others skilled in the art to make and use my invention, I will proceed to describe its construction and operation. i

A, is the steam cylinder having its piston rod B, connected with the pump rod.

C, is one of the pumps, of which there are supposed to be two, arranged side by side.

D, is the valve chest.

F is the main valve of the engine, which is of the well-known three-port kind containing two steam ports a, cz', and an exhaust port Z), working in connection with the usual arrangement of steam and exhaust ports c, c', d, in the cylinder.

E, E', are two adjustable shutters for varying the area of opening of the ports a, a, of the valve F, one for each port, said shut-- ters consisting of plates or blocks of metal of a size and form to cover the said ports a, a. These shutters are fitted to the back of the valve so as to be capable of sliding thereon thateither one may be made to cover a greater or less portion of its respective port or to leave the same entirely open or closed. They are made adjustable independently of each other by separate screws Gr and Gr', arranged parallel with the valve stem 0,' the former of which screws is made hollow for the stem of the latter to pass completely7 through it. rIhe threads of these screws G, G', tit to female screws provided in the shutters. The screw G is provided with a journal shouldered at its ends to lit into a journal box-f, provided for it on the back of the valve F, and so, while permitted toturn, it is prevented moving longitudinally independently of the valve. The said screw has a hollow cylindrical stem which works through a st-ufling box g, in the rear end of the valve chest D, outside of which it is furnished with a wheel or handle h, to turn the screw without opening the steam chest. The stem of the screw G', is filled with a stuffing box y', at `the outer end of the stem of the ters E, E', move along with the valve in the l screw G, and the gland of this stuffing box serves to act in combination with a shoulder within the last mentioned stem and a collar i, on the stem of the screw G', toprevent any longitudinal movement of the latter screw independently of the valve. The stem of G', is furnished like that of Gr, with a wheel or handle It', outside the valve chest to turn it.

In the operation of the engine, the shutsame manner as though they were permanently attached thereto, Vthe stem of the screw G, working back and forth through the stufling box g, as the valve travels, back and forth and the parts a, a', each always remaining in the same degree covered or uncovered till some variation is found necessary when either shut-ter may be moved in a direction to cover a greater or less portion of, or be made to entirely open or close its respective port by turning its respective screw by the handle or wheel it, or L, outside the steam chest.

As an illustration of the advantage re sulting from the application to the valve of the shutters above described, I will remark that in pumping-engines for mines it has been common to use a single-acting steam cylinder, and to apply the steam to operate in a direction to raise the pump-rods and plungers or pistons, and to make the latter heavy enough to descend and force up the whole column of water in the discharge pipe, but much difficulty has been experienced in constructing the pump rods of the proper weight for this pur-pose. Now, by using a double-acting engine with a shutter applied to the upper valve p ort as described and making the pump-rods somewhat lighter than is requisite to make them overcome the weight of the column of water, the shutter can be adjusted to give the upper port just opening enough to admitthe small quantity of steam above the piston that is necessary to make up for the deficiency in the weight of the rods, &c., and thus the whole diliiculty is overcome. I propose, in applying the invention to pumping engines, to use two force pumps driven by the same rod and to make the weight of the rod or rods which work rod to drive it down; and the same or nearly the same amount of steam will be requisite on the lower side of the piston to raise the rod and its appendages. It will thus be seen that the application of the adjustable shut ters to the .valve affords facility for regulating the admission of steam to either side of the piston as may be Arequired according to the force required in either direction.

H, is. the cylinder of the small engine by which the main valve F is operated; the piston I, ofthe said engine being attached to the stem e, of said valve F. This small engine is litted with a short slide valve m, of the common kind, which is connected with the arm n, of a rockshaft p, and the arm g, of which is operated upon to produce the necessary movement of the saidvalve m, by tappets fr', r, on a Yrod s, attached to and moving with the piston rodB, or said tappets may be on the piston rod itself.r t, is the exhaust passage of the cylinder H, having interposed between it and its escape pipe u, a valve box J, containing a slide valve L, whose parallel faces fit to slide between the back and front of the said box. This valve has in its bot-tom edge a tapering arched passage o, the larger end of which is next the steam cylinder H, and the smaller end next the entrance to the escape pi-pe; andv made to close a greater or less portion of the entrance to the escape pipe u, and so more or less to check the exhaust of steam from the cylinder H, andcause the cushioning of its piston I, as it approaches either end of the cylinder, thereby preventing it striking the ends ofthe cylinder. The stroke of the piston I, is also to some extent varied by checking the exhaust more or less, the stroke being shortened as the exhaust is more checked and vice versa. The object of the spring y, is to prevent the blowing out of the ends of the cylinder H, by the too great compression of the steam therein, such pressure acting against the tapered interior of the arched passage o, and raising the valve, and thereby uncovering a greater portion of the entrance to the escape pipe.

I do not claim the tting of plates or blocks to the back of a slide valve when they are intended to operate as cut-offs for using the stem expansively in the cylinder. But

What I claim as my invent-ion and desire to secure by Letters Patent, is:

1. The employment, in combination with a slide valve, of one or more shutters applied and secured thereto, substantially as described, to vary and regulate the area of opening of the port or ports, as and for the purposes herein specified.

2. Combining the two shutters E, E', (when two are employed) with the slide Or its equivalent and spring y, arranged and applied substantially as described, for the pur-pose herein set forth.

HENRY CLAYTON.

tnesses A. S. PORTER, PRESTON ROBINSON. 

